Re: [PATCH] fs/io_uring.c: convert put_page() to put_user_page*()

From: Ira Weiny
Date: Mon Aug 05 2019 - 18:04:45 EST


On Sun, Aug 04, 2019 at 07:32:06PM -0700, john.hubbard@xxxxxxxxx wrote:
> From: John Hubbard <jhubbard@xxxxxxxxxx>
>
> For pages that were retained via get_user_pages*(), release those pages
> via the new put_user_page*() routines, instead of via put_page() or
> release_pages().
>
> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions").
>
> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> Cc: linux-block@xxxxxxxxxxxxxxx
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>

Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>

> ---
> fs/io_uring.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index d542f1cf4428..8a1de5ab9c6d 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2815,7 +2815,7 @@ static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
> struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
>
> for (j = 0; j < imu->nr_bvecs; j++)
> - put_page(imu->bvec[j].bv_page);
> + put_user_page(imu->bvec[j].bv_page);
>
> if (ctx->account_mem)
> io_unaccount_mem(ctx->user, imu->nr_bvecs);
> @@ -2959,10 +2959,8 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
> * if we did partial map, or found file backed vmas,
> * release any pages we did get
> */
> - if (pret > 0) {
> - for (j = 0; j < pret; j++)
> - put_page(pages[j]);
> - }
> + if (pret > 0)
> + put_user_pages(pages, pret);
> if (ctx->account_mem)
> io_unaccount_mem(ctx->user, nr_pages);
> kvfree(imu->bvec);
> --
> 2.22.0
>